A study of model reactions for Schiff-base forming enzymes is proposed in order to assess the ability of amine groups to catalyze beta-keto acid decarboxylations, aldol condensations, dehydrations of beta-keto acids, isomerization of beta, gamma-unsaturated acids, and Michael additions to alpha, beta-unsaturated compounds. These reactions are models for acetoacetate decarboxylase, 2-deto-3-deoxy-L-arabonate dehydratase, and maleylacetoacetate isomerase. The work is designed to provide information on 1) the effect of amine basicity on rates and mechanisms of decarboxylation of beta-keto acids and retroaldol condensations of beta-hydroxy ketones, 2) the nature of the rate-determining step in the above reactions, 3) the possibility of amine catalysis of Michael addition reactions to alpha, beta-unsaturated carbonyl compounds and 4) the possibility of amine catalysis of dehydration of beta-hydroxy ketones and of isomerizations of beta, gamma-unsaturated carbonyl compounds to their conjugated isomers.